Energy detection technique for ultra-low power high sensitivity wake-up receiver

An energy detection technique for improving the sensitivity of an ultra-low power wake-up receiver is presented. This technique uses an envelope detector, an integrator and a comparator to reduce the excess noise introduced by wide bandwidth of IF gain stage. Theoretical analysis shows that with 10us integration time, it can effectively remove more than 15 dB of excess noise, bring the minimum required SNR for 10^-3 energy detection error rate down as low as -4dB. With an expected 18dB noise figure due to low current budget, the receiver could achieve -85dBm sensitivity. The performance can be further improved to -95dBm by increasing integration time to 1000us which leads to a trade-off between achievable sensitivity and wake-up latency.